Field
The present disclosure relates to a display device, and more particularly, to a flexible display device.
Description of Related Art
Various flat display devices reduced in weight and volume, compared with cathode ray tubes (CRTs) heavy in weight and large in volume, have been developed. Flat display devices include a liquid crystal display (LCD), a field emission display (FED), a plasma display panel (PDP), an organic light emitting display device, and the like.
Display devices, which are thin and lightweight, are commonly used as display units in mobile communication terminals or portable information processing devices. In particular, portable or mobile devices increasingly require display panels that are thinner and lighter and consume less power. Such display devices have been applied to various fields such as TVs, automobile displays, wearable devices, and the like, as well as mobile devices such as smartphones and table PCs. In order to be applied to various fields, display devices are required to be structurally deformed in various manners.
To meet the requirements, recently, flexible display devices that can be bent or folded have been actively developed. For example, flexible display devices may implement an input image on an active region of a display panel including a plastic organic light emitting diode (OLED). The plastic OLED may be formed on a bendable (flexible, pliable, or bowable) plastic substrate. Since flexible display devices are available for variously designs as requested, structural restrictions that may be caused in using related art display devices may be significantly reduced.
FIGS. 1 and 2 are views illustrating an example of a flexible display device. A flexible display device may be bent in a forward direction of a display device (inner curved), as shown in part (a) of FIG. 1, or in a backward direction of a display device (outer curved), as shown in part (b) of FIG. 1. When the flexible display device is bent, stress is applied on the display device.
When stress equal to or greater than breaking strength is applied to the flexible display device 1, signal lines 3 formed within the display device 1 may be cracked or disconnected. Cracks generated in the signal lines 3 may cause defective screen driving of the flexible display device 1, degrading product reliability and stability. In order to enhance reliability and stability of the flexible display device 1, a structural solution allowing the display device 1 to be stably bent is required.